Psychological preparation of children and their families for hospital and clinic treatments can reduce children's emotional stress before, during and after hospitalization. Current mental health practice in the United States, however, is apparently random, inconsis-tent and sometimes harmful. Mental health practices in pediatric settings have not been documented systematically, nor can they be easily learned about by practitioners. There are, however, programs of preparation that demonstrate effective methods, according to the few research studies available. These methods will be systematically described, reviewed and critically analyzed in one report, and practical as well as research issues of major significance will be discussed. Three collection methods will be used: (a) a comprehensive review of the experimental and clinical literature; (b) a questionnaire sent to every American facility offering pediatric services, with a follow-up to selected programs; (c) site visits in various parts of the country by trained observer-interviewers using a standard guide. A review and analysis of the resulting reports and collection of materials will document current mental practices in pediatric settings, suggest trends and identify significant areas for further mental health research. Such data could result in improved and more consistent effective psychological preparation of children to prevent the potential emotional trauma involved in medical or surgical treatment in pediatric settings.